That won’t work. The real issue is that I am attempting to monitor multiple FreePBX systems and just want to know if anyone is using an extension on that system.
Right now, I have one phone that I have as an extension on each of those systems. There are 8 FreePBX installations total. Each has their own normal extensions and trunks – they are completely separate systems. But, on my “monitoring phone”, I have 8 accounts – each with one extension on each system. I then have multiple “sidecar” extensions – which list a bunch of the BLFs for the extensions on each system. So, I’m kinda doing what you are talking about now. The problem is – it has gotten a bit crazy. I have 3 sidecars each with 20 BLFs – and I’m running out of spots.
My thought was that if I could do a BLF that tells me if any extension is in use, then I could compact this all down to a single sidecar that just tells me if anyone is currently using any extension on one of those systems. (Or, if I can’t get that, then just tell me if anyone is on an outside call if any trunk is in use.)